I have used a kit very similar to this one a few times.
Afterwards I have driven thousands of miles on the repaired tire. I once went into a local tire repair shop (old school kind where the owner works there, not the chain crap) and had a chat with them about tire plugs. It was the opinion of at least two of the tire guys that the plugs will outlast the rest of the tire and it would be a waste of money to replace it.
Do I agree with this? Not sure. However, if your goal is to get home, you cannot go wrong with one of these type kits.
Note - they can get real hard to use after sitting in a hot car for months. Check a couple times a year to make sure the plugs are still usable.